Electric elevator



(No Model.)

r A. T. CHASE.

ELECTRIC ELEVATOR.

No. 508,680. Patented Nov. 1-4, 1893..

F'|E I WITNESSES A INVENTDR 088 8% W 5 UNrrnn TATES Fries.

PATENT ARTHUR TAFT CHASE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNUR TO THETHOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT ELECTRIC ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 508,689, dated November14, 1893. Applicationfiledbecember16,1891, Serialllo. 415,223.(Nomodel-l To whom it may concern:

Be it known that I, ARTHUR TAFT CHASE, a citizen of the United States,residing at Cambridge, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inElectric Elevators, of which the following is a specification. Thisinvention relates to improvements in circuit controlling devices forelectric ele- ID vators, the object of the invention being to break thecircuit through the field magnet, at times when the elevator is not atwork for a considerable period, so as to economize the current used.

As is well known there are times, frequently of considerable duration,during which an elevator is not at work, the elevator cal) being at suchtimes, usually at the bottom of the hatchway. In the case of electricele- 2o vators when the current is kept turned on through the fieldmagnet during such times, a considerable waste of electric energyoccurs. To obviate this waste, I take advantage of the above mentionedfact that when the elevator is not running the cab is usually at thebottom of the shaft, with its door and the door into the hatchway atthat point open. On one of these doors, for example, the hatchway door,I place a projection or sL-iker, 0 which when the door is opened engageswith a switch connected to the field magnet circuit of the elevatoroperating motor, so as to cause such circuit to be opened and cut offthe current from the field magnet; When 5 the door is closed a reversemotion of the switch is effected, again energizing the field magnet andputting. the motor in operative condition.

In the accompanying drawings, Figure 1 is an elevation of a portion ofthe lower part of the hatchway, showing the door, the striker thereonand the switch operated thereby.

Fig. 2 is a vertical section on the line 2-2 in Fig. 1, also showing aportion of the cab. Fig.

3is an enlarged view of the switch in the open position. Fig. 4 is adiagram of the circuit connections.

A represents a part of the elevator shaft,

13 the cab and C an elevator door onthe lower or ground floor. An arm orprojection D attached to this door extends upwardly and carries ananti-friction roller 01, which, when thedoor is moved in one directionor the other, engages with the forked end 6 of an arm of a double-poleswitch E, which is placed in or near the hatchway, and controlsthecircuit of the field magnet of the elevator operating motor.

As shown in Fig. 3 the switch may consist .of two metal arms 6, epivoted at land 2 re- 6o spectively, connected by an insulating link eso as to have a parallel motion, and. engaging with contacts 3, 4:. Theline connections 1,1 from the constant potential circuit are brought topivots 1 and 2, and the field magnet or motor connections fif, lead fromcontacts 3, 4. When the elevator door is closed, as shown in Fig. 1, theswitch levers e, e engage with the contacts 3, 4, closing the fieldmagnet or motor circuit, and the roller 01 7o stands somewhat to theright of the fork e formed on the end of the switch lever 6 Now when thedoor is opened by sliding it to the left, the roller 01 strikes an armof the fork e and throws the switch to the position of Fig. 3, and thenpasses on to the end of its travel. When the door is again closed, theroller returning, strikesthe other end or arm of the fork, and carriesthe switch back. In order to insure this operation, to provide a quickbreak, and to hold the fork in its extreme position on either side so asto engage properly with the roller, 1 provide'a doublethrow spring 5which may be attached at one end'to a fixed support and at the other endto 8 5 the lever 6 so as totend to hold the switch levers at either oftheir extreme positions, and to quickly bring them to such positions assoon as they have once passed the central position. go

As before stated this invention is especially adapted for use with aconstant potential circuit, the leads L, L of which are indicated inFig. l, connections Z, Z being taken through the switch E andconnections f to the field magnet F.

In derivation with the field magnet circuit is the armature circuit a, aincluding the armature A of the elevator operating motor, and acontrolling rheostat and circuit breaker 10o R having resistances r aseries of contacts 7' therefor, line terminals Z Z and a controllingswitch lever 25, which co-operating with the line and resistancecontacts, serve to make, break, reverse and vary the resistance of thearmature circuit. Any other approved form of controller for the armaturecircuit of the motor may however, be adopted in place of that hereshown.

My invention relates more particularly to the combination with anarmature circuit having a controlling means therein, of a derived fieldmagnet circuit having connections to the line independent of the circuitcontroller in the armature circuit, but controlled by an independentswitch which may be left closed during such ordinary reversals andstoppages as occur while the elevator is running up or down the shaft,and may be opened at times when the elevator is stopped for such aperiod as to make it desirable to save the waste of current through thefield magnet. The circuit breaker controlling the field magnetconnections may obviously be operated in other ways so as to obtain theabove result. For example, the striker D may be attached to either thehatchway door, as shown, or to the cab door, or to any other movablepart within reach of the elevator attendant when the cab is in aposition at which a long stop is likely to be made.

It is desirable to make the circuit breaking switch e, 8 open theconnections of both the field magnet and the armature circuits, so as toprevent the possibility of the current being turned onto the armaturewhile the field magnet is inactive. I therefore prefer to derive thearmature and field circuits from common connections controlled by thisswitch as shown atfif, in Fig. 4.

What I claim as new, and desire to secure by Letters Patent, is-

1. In an electric elevator, the combination with the cab carrying acontrolling device for the armature circuit, of a double pole switchcontrolling the line connections to the field magnet and armature andlocated near the ole vator shaft, and a door giving access to said shaftand having an arm to positively open said switch when the door isopened, and vice versa, substantially as described.

2. In an electric elevator, the combination with the cab B, of thearmature controlling device mounted in the cab, the shunt wound motor,the spring actuated double pole switch controlling the connections fromthe mains to the motor and having a fork c, and the elevator shaft door0, carrying an arm I) adapted to strike and operate the forke both inthe opening and closing of the door, substantially as described.

In witness whereof I have hereunto set my hand this 11th day ofDecember, 1891.

ARTHUR TAFT CHASE.

Witnesses:

A. P. KNIGHT, O. L. HAYNES.

